TJ turns over but won’t start

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Member

I have done several searches on this forum and others for a similar situation, but no luck. My 1997 TJ 4.0, 5 speed manual will crank over but wont start. I replaced the engine and on initial start it fired up and ran for about 10 minutes and then started to miss on reving the engine. I shut it off and then tried to start it again and it will just cranck. I checked the distributor and it is facing the #1 cylinder on top dead center. I have spark. My fuel rail pressure is 45 lbs. Each fuel injector is between 12.1 and 12.3 ohms. I thought it might be the Crank Position Sensor. I changed it and I still have the same result. I am not getting any codes either.
I am up for any suggestion.
Thanks,
Igoo65

New Member

I had a similar situation with my 04.. Not sure if its the same on your but after scratching my head for days I got a mopar CPS and with a little help from the girl i got her running perfectly. Is your CPS adjustable? I know this is frowned on but i had the old lady sitting in the jeep turning it over wile i slowly "adjusted" the CPS and when it fired up i tighten it down and never had another issue with it after that!

Member

I got CPS from Napa and it is not adjustable. I'm not sure the one I took off was actually bad. When I tested it I was getting 6.02 ohms and it should read infinity. I put a new one on and it still just cranks. I retested the old CPS out of the Jeep and it test OK. I put the engine back to TDC and checked the distributor again and it is in the correct position at #1. I am very confused.

zombicon

Try spraying carb cleaner or starting fluid in the air filter. See if it wants to start. If it does it is most likely a fuel issue. If you are positive you have spark then do a compression check. Make sure your new motor is actually good to go.

Earlier I was helping someone on this forum that said they had spark then later told me they changed the coil and that fixed the problem which tells me they didn't really have spark, so check at the plugs to see if you have spark.

It sounds like you are pretty confident that you have fuel because your pressure seems right on, but make sure you have spark at all of your plugs. Double check the cap for moisture or carbon tracks. Make sure the coil wire is pushed all of the way in and on the coil.

Pull the spark plugs and lay them out in order that you pull them in case one is a different color that could tell you that you are having an issue with that cylinder. Say all are white but one is dark, that could tell you you have a problem in that cylinder. Also can could be more than one cylinder.

Member

So here’s what I found out this morning. My distributor was 180° out at top dead center. This had actually happened a couple times Yesterday. I thought I was losing my mind because I could have sworn I put the distributor in correctly. A friend came over and reset the distributor and it fired right up. About 10 minutes later after running it started missing again and then wouldn’t start again after I had turned off the engine. There doesn’t seem to be anything wrong with the distributor the shaft and gear are intact and tight. I am at a lost! Anyone have any suggestions?

Member

Has anyone heard of a distributor jumping to 180 degrees out while running? I have the distributor locked down. This is a brand new engine. The distributor looks to be ok. All of the roll pins are intact. I can't figure why this thing is jumping to 180 out. Anyone?????

TJ Expert

Member

OK new distributor set at TDC on the compression stroke. New CPS. 44-45 psi of fuel pressure. 12 ohms on each injector. Spark at coil and spark plugs. Disconnected battery to reset PCM. New gas in tank. I sprayed starting fluid across the throttle body. Just cranks, no start. Anyone have any suggestions?

TJ Expert

But anyone else, parking in a heated garage when it is like 0F outside. A heated garage will have a higher humidity than the frigid outside and water vapour moves to eqilibrium so water vapour will enter your tank. When you leave the garage the cold plus the wind chill will freeze that vapour. And those crystals can block the injectors.

Best way to avoid it is keep the gas tanks full, no air, less vapour to equalize, and park outside where there is no excessive water vapour.

Member

I’m in Colorado and it isn’t freezing and my gas tank is full. My Jeep hasn’t been outside since I pulled the engine out. I’m pretty sure water in my gas is not the problem. Please see previous post on what is happening with my engine not starting!

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Produced from 1997-2006, many consider the Jeep Wrangler TJ to be the last true Wrangler. I started Jeep Wrangler TJ Forum to serve as a resource for TJ owners around the world. You'll find everyone here to be friendly, and most importantly, drama free!